//mySerial.print("AT+PIN1234"); // Set pin to 1234 was 1342
//delay(1000);

//mySerial.print("AT+NAMEJY-MCU-HC06"); // Set the name to JY-MCU-HC06
//delay(1000);

//mySerial.print("AT+BAUD4"); // Set baudrate to 9600
//mySerial.print("AT+BAUD7"); // Set baudrate to 57600
mySerial.print("AT+BAUD8"); // Set baudrate to 115200
delay(1000);
}

void loop() // run over and over
{
if (mySerial.available())
Serial.write(mySerial.read());
if (Serial.available())
mySerial.write(Serial.read());
}

Now I'm unable to revert back to the default settings (baudrate 9600 and name HC-06) and I don't how to fix this.

I tried entering serial AT commands but I get no response. I also made sure the HC-06 module is not paired with any other device, but still no response. I also tried different sources and terminals besides the Arduino Serial monitor, like: